I've generally found this kind of thing annoying in my various attempts to learn languages - in one of my high school spanish classes the teacher thought it was important to have us learn a little song to memorize the six present tense forms of the to-be verb ser: (yo) soy, (tu) eres, (el/ella) es, (nosotros) somos, (vosotros) sois, (ellos/as) son. My thinking was, there's only six forms to memorize, and the verb is an incredibly common one ("to be"!) so they'll get constantly reinforced anyway. The song is silly and isn't really helping anyway.

I feel similarly about the transformations for the Japanese -te forms and -ta past tense marker. The entire system is:

Ichidan: add -te/ta to stem Godan: -u/ru/tsu -tte/tta -su -shite/shita -mu/bu/nu -nde/nda -ku -ite/ita -gu -ide/ida

So basically ten patterns which group into 5 subpatterns. There's some logic behind them - the -te and -ta morphemes originally got added to the -i/pre-masu/ren'youkei stem and then underwent some idiosyncratic consonant reductions in godan verbs. But, really, it's only ten patterns, you can just memorize them; and these are incredibly common verb forms that get used all the time so you'll have them reinforced frequently if you are at all engaging with the language. It's a lot less to memorize than if you were learning Ancient Greek or Sanskrit or something.